Heat exchanger



Oct. 26, 1943. F. R. HIGLEY HEAT EXCHANGER Filed June 8, 1940 3Sheets-Sheet l v! u m H m H m F Oct. 26, 1943. F. R. HIGLEY HEATEXCHANGER Filed June 8, 1940 3 Sheets-Sheet 2 INVENTOR. Fen/vale. H/ausrATTORNEYfi Oct. 26; 1943. F. R. HIGLEY HEAT EXCHANGE}?- Filed June 8,1940 5 Sheets-Sheet 3 INVENTOR. ear/x8 f/lLEY MQam KM ATTORNEYS PatentedOct. 26, 1943 UNITED STATES PATENT OFFICE HEAT EXCHAN GER Frank R.Higley, Cleveland Heights, Ohio, assignor to The Bryant Heater Company,Cleveland, Ohio, a corporation of Ohio Application June 8, 1940, SerialNo. 339,517

7 Claims. (Cl. 126--110)- This invention relates to improvements in heatcentral rotors are employed for circulating air or other fluid, theusual practice is to circulate the fluid to be treated over a coil ofpipe. That practice is not efficient in certain respects because therotor induced flow is interfered with to a large extent by such coiledpipe. In accordance with the present invention a radial diffuser orstator is employed which enables th rotor to build up static pressureand to move large quantities of air or other fluid with a high degree ofefi'iciency, while at the same time eflecting good heat transfer.-

One' of the objects of the present invention therefore is the provisionof a heat exchanger which is highly efiiclent because of its capacity tohandle large quantities or fluid in relation to the size or theapparatus.

Another object of the invention is the provision of a heat exchanger ofthe character stated that is adapted to be mounted centrally of aceiling,

floor, or wall panel of the space or compartment in which the air is tobe conditioned.

Another object is the provision of a heat ex changer of simple designand small number of parts, with a consequent reduction of cost.

.A further object of the invention is the provision of a heat exchangerso arranged and constituted as to lend itself to the employment of aheat transfer member of aluminum or the like having high thermalconductivity.

Other objects and features of novelty will appear as I proceed with thedescription or that embodiment of the invention which, for the purposesor the present application, I have illustrated in the accompanyingdrawings, in which Fig. 1 is a central vertical sectional view of aheater embodying the invention.

Fig. 2 is a horizontal sectional view taken substantially on the line2-2, Fig, 1, looking in the direction of the arrows.

Fig. 3 is a horizontal sectional view taken sub stantially on the line3-3, Fig. I, looking in the direction of the arrows.

' Fig. 4 is a further horizontal sectional vie taken substantiallyon'the line 4-4 of Fig. 1 looking in the direction of the arrows.

Fig. 5 is a conventionalized elevational view partly in radialtransverse section of another form of the invention adapted particularlyfor applications in which the heating or cooling fluid is other thanproducts of combustion.

Fig. 6 is a sectional view of the invention disclosed in Fig. 5, theview being taken substantially on the line 61-6 of Fig. 5, and

Fig. 7 is a further sectional view taken substantially on the line '|-lof Fig. 5.

Referring first to Figs. 1, 2 and 3, wherein is illustrated a gas firedheater embodying the invention, i0 is a ferrous metal casting ofgenerally circular form in plan, which has a central opening ll definedby a wall l2. A second wall l3, concentric with wall l2, together withthe latter wall defines an annular chamber or passage I! which has agate i5 formed by interrupting the wall It at one point. Starting at thewall I3 the bottom of the casting i inclined upwardly and outwardly andterminates in a horizontal flange it which extends completely around theperiphcry of the casting. At a point opposite the gate IS the casting isshaped to form a horizontal exit I! for the combustion gases. On theside of the casting remote from the gate t5 the walls i2 and it arecontinued downwardly as shown at 08 and i9 and joined by radial walls 20and 2| to form a. combustion chamber 22 below which a burner 23 ismounted. I

A cylindrical guard and concealing wall 28 is suspended concentricallybeneath the casting ill by means of a plurality of straps 25, secured toand depending from the casting to the lower ends of which the guard wall24 is welded. A second cylindrical member 28' of smaller diameter ismounted concentrically within the guard wall 24 by suitable meanswhichmay comprise screws 9 threaded into the inner wall l8 of thecombustion chamber and straps 25' similar to the straps 25 abovementioned. The member 26 is of approximately the same diameter as thewall i2 of the casting and is in substantial alignment therewith, thetwo elements i2 and. 26 together defining an air inlet passage to thefan 38. A burner mixer tube 2'7 extends through the cylindrical member26 and is joined by connections 28 and 28 with fuel control apparatus 30and 3| situated between the cylindrical elements 24 and-26. The burnerwith its gas connections and control aparatus may be supported bysuitable means from one 01 both of the cylindrical elements 24 and 26.The arrangement illustrated keeps the burner apparatus largely out ofthe main path of the entering air and prevents any currents of air frompassing over the burner aside from'those which travel-upwardly throughthe combustion chamber 22.

The casting l between the wall l3 and the flange I6 is open at the topand in this opening there is mounted an annular horizontal dividing -orpartition wall 32, formed preferably of nonferrous high thermalconductivity metal, such as aluminum. The engaging, surfaces of thecasting and partition wall are machined so that tight joints result.About midway between the inner and outer edges of the partition wall 32there is a depending fin or rib 33 which extends downwardly far enoughto meet or substantially meet the inclined bottom wall of the castingl0, and on each side of this wide rib there are one or more narrowerfins or ribs 34 and 35. Hereinafter the term fins is to be understood asa generic term applying to any or all of the parts 33, 34 and 35, whilethe term rib is to be understood as a specific term applying only to thepart 33. The fins 34 and 35 are completely annular although reduced indepth at certain points, but the rib 33 has an opening 36 therethroughforming a gate spaced 180 from the gate l and connecting the annularpassages on ing .the fins 34 as well as the rib 33, until they meet atthe opposite side of the unit and flow out through opening 36 into theannular passage .on the outer side of rib 33. Here they again divide andtravel in opposite directions toward the right, as viewed in thedrawings, wiping over the wide rib 33 and the fins 35, and passing outthrough the exit i'l.

vanes 31, formed integral with the wall [2 of the casting to, extendinto the central opening Ii and serve to increase the surface area ofthe heated wall it by means of which heat is im parted initially to theentering air.

Arranged centrally above this air intake opening H is a centrifugal fan38, which rotates in the direction of arrow A, Fig. 2, and the blades 39of which have.a convex curvature on their forward surfaces. This rotorputs a suction drag on the air rising through the opening H and expelsit centrifugally at all points in the circumference of the unit, thepath of travel of any particle out of the rotor during the operation ofthe latter at the preferred speed being indicated approximately by thearrow B in Fig. 2. Inasmuch as the direction of the air delivered by therotor depends to some extent upon the speed of the rotor, I preferto'employ a constant speed motor 42, as for example a synchronous motor.The direction of discharge from the rotor then remains constantregardless ofthe load imposed upon the motor. Vanes 40 project upwardlyfrom the partition wall 32 with which they are integral. These vanes arepreferably quite numerous and therefore greatly increaseare curvedhowever throughout approximately two-thirds of their length and areformed to gradually direct the air flow to a radial direction 0, theouter one-third of the length of each fin or vane being straight anddisposed in a. radial position. 1

All of the vanes 40 plus the partition wall 32 and the cover presentlyto he described together form a radial diffuser and stator which, in thepresent invention, has in addition to the usual functions of diffusersand stators the function of transferring heat. It serves to build uppressure, which is important for the circulation of air to be treated,and it does not interpose obstacles 'to air flow to anything like theextent of theusual pipe coil or other conventional radiator. In order tobetter distinguish the invention from the prior constructions, the termdiffuser as hereinafter employed is to be understood as a chamberextending about a centrifugal impeller within which kinetic energy isconverted to pressure energy.

A pressed sheet or cast metal cover plate 4| arranged centrally extendsover the fan 33 and has a depressed rim which rests upon the inner endsof the vanes 40. Motor 42 is secured centrally to this plate and has adepending shaft 43 extending through an opening in the plate.

the' effective surface of the partition wall 32 on v its upper surface,thereby giving that surface the capacity to transmit heat to the airmore rapidly than heat is absorbed by the lower surface of thepartition. In the present instance the vanes 40 at their inner ends arearranged at substantially the same angle as the arrow B, so that minimumresistance is presented to the air as it is delivered by the rotor. Thevanes 40 The hub of the fan is secured to this shaft. An annular coverplate 44 extends over and enages the upper edges of the vanes 43 and isformed along its inner portion to overlie a portion of the plate 4|.

The plate 4| is held in position by stud bolts 45, preferably three innumber, which have reduced lower ends that are threaded into tappedholes in the casting l0 and reduced upper ends which-pass through holesin plate 4| and receive nuts 46 that are threaded down against the plateto hold it in place. Suitable holes 41 are formed in the plate 44 toclear the nuts 43. The inner edges of the annular plate 44 are fastenedto plate 4! by short machine screws 43.

The heater is supported at spaced points of its periphery by a pluralityof rods 49, preferably three in number, which extend downwardly throughsuitable holes in the plate 44 and washers 50 welded to the plate, andthence downwardly through holes in the partition wall 32 and in theflange it of the casting l0. Nuts II threaded on the lower extremitiesof the rods support the casting i0, and nuts 52 on the rods above theplate 44 serve to press that plate down tightly against the vanes 40 andthrough the intermediacy of the vanes to cause the partition 32 totightly engage the flange II. The bolts 45 and the rods 43 are lined upwith certain of the vanes 40, which vanes are shortened sufficiently forthe purpose. in order to present as little resistance as possible to airflow.

Access may be had to the fins 33, 34 and 33 for the purpose of cleaningproducts of combustion therefrom, by unthreading nuts 32 and removingscrews 43, after which the annular, plate 44 may be pushed up on therods 43 out of the way of the workmen and the casting may be liftedstructions providing paths of somewhat different character may be usedif desired without departing from the spirit of the invention so long asthey cause the hot gases to wipe the partition mum temperature at thelower portion.

wall 32 and the fins thereupon in such manner that a good rate oftransfer of heat from the 'gases'to the partition wall is effected. Itwill also be appreciated that while the disclosed relation of gaspassages and air passages is preferred, it is nevertheless within thepurview of the invention to position the annular gas passages above theair passages instead of below them.

Obviously, the rotor 38 will tend to have maximumdischarge adjacent itsdisc portion, so that when disposed as in Figure 1, with the discuppermost, a characteristic of the discharged stream will be maximumflow at the top. Equally obviously, the lower part of the stream,closest to the wall 32, will receive maximum heat. Thus any tendencytoward Stratification of the stream discharged from the apparatus willbe toward maximum flow at the upper portion and maxi- Such streamcharacteristic will tend to project the hot stream farther into thespace to be heated and with less tendency to rise than would otherwisebe the case.

In Figs. 5, 6 and 7 I have illustrated a second form of the invention inwhich the heat ex changer is designed either to heat or to cool airpassed through the device by the rotor. In this modification, as in theone first described, there is an annular heat exchange member with apartition wall 55 upon one surface of which are ribs or fins whichextend around the member, and upon the other surface of which there area multiplicity of vanes that are wiped by the air as it flows throughthe apparatus. In order to attain the highest efficiency this heatexchange member should be constructed of a material of high thermalconductivity, as for aluminum.

On one side of partition wall 55 this annular member is formed with fins55, 51 and 58, with an outer rim 59, an inner wall member 6|] and tworibs SI and 62. These ribs and fins act to guide the hot or cool fluidwhich is caused to flow over one surface of partition wall 55 and actalso to abstract or give up heat, as the case may be. As here shown theyare generally circular, but the fins 58, 51 and 58 are interrupted atdiametrically opposite points, the rib BI is diverted a sufiicientamount to include an intake conductor 63 and example at a diametricallyopposite point is interrupted;

while the rib 62 is interrupted at the right-hand side only of theapparatus as viewed in Fig. 7. The hot or cold liquid or other fluidentera through the conductor 63, divides and flows in two semi-circularpaths towards the left, then fiows through the interrupted part of rib66 at the left of the figure into the middle pass between ribs SI and62, where it divides and flows towards the right. At the right-hand sidethe two streams again meet and flow through the inter= rupted part ofrib" into the outer pass, where it again divides and flows back to theleft and leaves through the exit conductor 84.

An annular cover plate 65 which may be a stamping or other ferrous metalmember, closes the compartment just describedyengaging the two ribs 8iand B2 in order to form separate paths for guiding the fluid aspreviously described. This cover plate as illustrated herein may bemerely a flat plate which, after being placed in position, is held andsealed at its inner perimeter by a lip 66 that is' spun down against theplate. The periphery of the plate may then be turned down and under aprojecting shoulder on the rim II, as illustrated in Fig. 5.

Extending from the opposite surface of the partition wall are amultiplicity of vanes 81 that are relatively deep as compared with thefins and ribs 56, 51, 58, SI and 62.. .These vanes may be of the formillustrated in Fig. 2, or they may be straight as shown in Fig. 7. Ineither event however their inner ends are disposed in the direction ofrotor discharge, so that at their inner ends at least they willinterpose as little resistance as possible to the of fluid delivered bythe rotor, the angular direction of which is indicated by the arrow D.

Integral with'the annular member above described, I may form a circulargrill 68. A sheet metal plate 69 forms a closure for one side of theapparatus. It tightly engages the vanes 61, being held in place partlyat least by nuts 10 on the threaded extremities of the conductors 63 and64. The plate 69 is provided with a central depression in which issupported the motor ii, and around this depression at intervals thereare small ports 12 through which air may enter.

the grill 68, is subjectedto centrifugal force by the blades of a rotor13 which causes the air to be delivered into the stator-diiiusercomprising the vanes 61. For some purposes, particularly where theapparatus is set into a wall panel, the periphery of the plate 69 may beextended and dished so that the air will be directed out into the roomor other space to be conditioned. In this case air entering through thegrill 68 may be recirculated air, while that entering through openings12 may be fresh air.

Where the vanes 61 deliver air in a non-radial direction, as they do incases where the vanes are straight as herein illustrated, the directionof the discharge of airfrom the apparatus is varied further by thedished outer portion of plate 89 as indicated by the arrow E.

Having thus described my invention, I claim:

1. In a heat exchanger, a housing adapted to be supported from abovehaving a lower annular portion around which hot fluid is adapted to flowand an upper annular portion through which a fluid to be heated isadapted to flow outwardly in all directions, said exchanger comprisingan annular partition wall between said portions formed of non-ferrousmetal of high thermal conductivity and having a rib extending downwardlyto the base of the housing, whereby said rib transfers heat, guides thehot fiuid in its flow through the said annular portion and alsoconstitutes a support for the partition wall.

. 2. In combination. a heat exchange member comprising an annularpartition having on one side thereof integral fins running around themember, certain of said fins being deeper than the other andconstituting ribs adapted to serve as guiding means for directing hotfluid in curved paths around the member, said member having on itsopposite side integral vanes extending from the periphery toward thecenter of the member over which air to be heated is adapted to wipe inmoving outwardly from the center of the memher, a cover plate forengaging said vanes along their edges opposite said partition and aclosure for the finned side of said heat exchange member engaging saidribs, said closure having entrance and exit openings for hot fluid, andmeans for forcing air outwardly through said vanes.

3. In a heater, a casting of generally circular form, means'forsuspending the casting, said casting having annular cavity therein openat the top, 'a second casting comprising an annular partition memberclosing said cavity and provided with a plurality of depending finsextending into said cavity and formed to guide hot fluid in pathsrunning around the annular member, said first named casting having anintake for admitting hot gases to said cavity and a discharge port forexhausting them therefrom, said second casting having a series ofintegral vanes extending upwardly from said partition member, a coverfor the upper edges oi said vanes, a rotor positioned concentricallywithin said vanes and adapted to take air from below and discharge itthrough said vanes, two concentric cylindrical members hung from saidfirst named casting, a gas burner arranged between said concentriccylindrical members, and means for conducting products of combustionfrom said gas burner into said intake.

4. In a heater, a casting of generally circular form, means forsuspending the casting, said casting having an annular cavity thereinopen at the top, a second casting comprising an annular partition memberclosing said cavity and provided with a plurality of depending finsextend ing into said cavity'and formed to guide but fluid in pathsrunning around the annular member, said first named casting having anintake for admitting hot gases to said cavity and a discharge port forexhausting them therefrom, said second casting having a series ofintegral vanes extending upwardly from said partition member, a coverfor the upper edges 01 said vanes, a rotor positioned concentricallywithin said vanes and adapted to take air from below and discharge itthrough said vanesytwo concentric cylindrical members hung from saidfirst named casting, a gas burner and fuel control mechanism thereforlocated between said concentric cylindrical members, and means forconducting products of combustion from said gas burner into said intake.

5. In a heat exchanger. an annular conductor for hot gases having aplurality of interconnected concentric passes, ferrous means for housingthe innermost pass, means for housing the remainder of said passescomprising an annular casing having a ferrous metal wall and a wall ofthermal conductivity greater than that of the ferrous metal wall, vaneson the opposite side of said latter wall, means for feeding hot gasesinto said innermost pass and discharging them from the outermost pass,and concentric impeller means for drawing fluid into the exchangeraxially and discharging it centrifugally through said vanes.

6. In an apparatus of the class described, an annular heat exchanger,means arranged adjacent said heat exchanger to provide an air diffusionpassage bounded on one side by a face of said exchanger and dischargingperi herally thereof. and a centrifugal blower rotor arranged concentricof said heat exchanger to receive air from the central opening of thelatter and force said air into said diffuser in contact with said heatexchanger face, said heat exchanger having vanes extending into saiddiffuser and disposed each with its inner extremity in the direction ofrotor discharge and thence with curvature in one direction until itsouter extremity is radial.

'I. In apparatus of the class described, a centrifugal rotor disposedwith its axis upright and arranged to. take air centrally and dischargeit peripherally, a stationary diffuser disposed about said rotor toreceive air therefrom and discharge it peripherally and comprising anupper confining member and spaced therebelow an annular heated member,whereby characteristics of the discharge from said diffuser will includea tendency toward maximum velocity at the upper part of the stream andmaximum temperature at the lower part of the stream\ FRANK Pt. HIGLEY.

